Cardiovascular reflexes and their roles in the neurohumeral control of the circulation have been investigated extensively. One reflex that has received very little attention is the vestibulosympathetic reflex. Despite the fact that the vestibular system has been shown to alter sympathetic outflow in animals, little is known about the vestibulosympathetic reflex and its function in humans. In this project, we plan to investigate the muscle sympathetic nerve activity responses to neck flexion, dynamic head movements and neck flexion in conjunction with other cardiovascular reflexes to better understand the vestibulosympathetic reflex.